Concrete sleeper and solid carriageway

ABSTRACT

A concrete sleeper for a solid carriageway, having a fixing block, which is inserted with the upper section thereof into an underside recess in the concrete sleeper, is mounted elastically by a ring produced from an elastomer and which can be inserted with the lower section thereof into a fillable cut-out in a top layer of the solid carriageway. A base made of an elastic material is arranged on the underside of the concrete sleeper.

The invention relates to a concrete sleeper for a solid carriageway, with an anchor block, which is inserted with its upper section into an underside recess in the concrete sleeper and is mounted elastically by means of a ring produced from an elastomer and which can be inserted with its lower section into a fillable clearance in a top layer of the solid carriageway.

In DE 202 13 667 U1, a concrete sleeper for a solid carriageway is proposed. The solid carriageway comprises a lower supporting layer, a first applied asphalt layer and a second asphalt layer, applied as a top layer. The top layer has clearances, inserted in which is an anchor block, which is consequently arranged with its lower section in the clearance and with its upper section in the underside recess in the concrete sleeper. The concrete sleeper is formed as a wide sleeper, i.e. only a small distance is provided between two adjacent concrete sleepers. Such a solid carriageway is offered by the applicant under the name Getrac (registered trademark).

A similarly constructed solid carriageway is described in DE 102 30 740 A1. The elastic ring arranged between the concrete sleeper and the anchor block is conically formed on its outer side, thereby making insertion easier. On the underside of the concrete sleeper there is a thin nonwoven, to compensate for any possible unevenness of the top layer. Since the concrete sleeper is hard-bedded because of the hard supporting layers, which in the case of this system are usually produced from asphalt, it is usually mounted with a highly elastic fastening, which can absorb the loads occurring when it is passed over by rail vehicles and distribute them in the longitudinal direction.

Such solid carriageways with elastic intermediate layers represent a mass-spring system, by which tremors and structure-borne sound can be transferred to adjacent surface areas, buildings and structures. These waves may both cause noises in the audible frequency range (secondary airborne sound) and cause vibrations of the ground or of buildings. When designing such a solid carriageway, it is therefore endeavored to fix the frequency range and the amplitude of the vibrations produced such that the tremors or the sound generated can remain restricted to certain frequency ranges that do not represent any disturbance.

The invention is therefore based on the object of providing a concrete sleeper for a solid carriageway by which tremors are transferred to a lesser extent to adjacent areas.

To achieve this object, according to the invention it is provided in the case of a concrete sleeper of the type mentioned at the beginning that a base of an elastic material is arranged on the underside of the concrete sleeper.

The invention is therefore based on the finding that a considerable improvement, i.e. a reduction, in vibrational emissions can be achieved by the spring of the mass-spring system being chosen to be as soft as possible while compatible with the permanent way and by the mass arranged above the spring being increased.

In the case of conventional solid carriageways, only the highly elastic rail fastening has resilient properties. The concrete sleeper, which may have a considerable mass of 300-1200 kg, is however mounted hard on the top layer in the case of the conventional solid carriageway.

According to the invention, by contrast, a base of an elastic material is arranged on the underside of the concrete sleeper, whereby the mass (concrete sleeper) mounted on the spring (base) is increased considerably in comparison with an only elastically mounted rail of a conventional solid carriageway. Tests have shown that, as a result of the concrete sleeper according to the invention, tremors are transferred to a lesser extent to the surroundings in comparison with a conventional solid carriageway.

The base of the concrete sleeper according to the invention may be produced from an elastomer; particularly preferred in this case is EPDM (ethylene-propylene-diene monomer). The base may be unattached or alternatively connected to the concrete sleeper, for example adhesively bonded.

In the case of the concrete sleeper according to the invention, the base is designed according to static and dynamic requirements; in particular, the thickness and the stiffness of the base are set such that, when it is passed over by a rail vehicle, a required or desired settlement that is also compatible with regard to the stability of the rails is achieved. The base may preferably have a thickness of between 6 mm and 20 mm; a base thickness of between 8 mm and 14 mm is particularly preferred. In the case of such a base, the settlements may reach 1.5 mm to 4 mm.

In order to improve the mechanical strength of the base of the concrete sleeper according to the invention, the base may be provided with a nonwoven on one or both sides.

A development of the invention may provide that the base has a clearance in the region of the underside recess for the anchor block. If appropriate, this clearance may also be provided at the ends of the sleeper. This clearance may be circular or square, so that the anchor block can be mounted without any problem. The anchor block does not necessarily have to be round or cylindrical, it may furthermore also be rectangular or hexagonal. Alternatively, the base may be formed as two parts, in that a first base section is arranged under one sleeper block and a second base section is arranged under the second, opposite sleeper block. Depending on the respective design, it may also be provided that the base is not formed with its full surface area under a sleeper block or a rail bed; instead, it may for example be formed as a strip that is made narrower than the rail bed.

It is also conceivable that the anchor block of the concrete sleeper according to the invention has a step with a downwardly increased diameter, the outer edge of the step preferably being rounded. The rounded step prevents the ring produced from the elastomer from being damaged by settling movements that occur millions of times during operation.

Since, unlike in the prior art, there is no sharp edge at this location, damage to the elastomer ring is avoided.

The width of the step of the anchor block may in this case be set such that the ring lies approximately with half its radial width on the step of the anchor block.

It is also within the scope of the invention that the underside recess in the concrete sleeper has a peripheral, preferably rounded step, against which the ring lies with its upper outer corner. The ring preferably lies approximately over half its radial width against the step of the concrete sleeper. This means that the ring, which has a rectangular or approximately rectangular cross section, lies with contact at two diagonally opposite corner points, so that when subjected to loading it undergoes a shearing deformation and deforms in a way similar to a parallelogram. The cause of this deformation is that it lies on the one hand with its upper, outer corner against the step of the concrete sleeper and on the other hand with its lower, inner corner against the step of the anchor block. If the concrete sleeper is subjected to vertical loading when it is passed over by a rail vehicle, first the base of the concrete sleeper and at the same time the ring undergo a vertical spring deflection; horizontal forces occurring are introduced into the supporting layer via the anchor block. The ring is preferably circularly formed; also conceivable furthermore are other configurations that are adapted to the cross section of the anchor block, for example the ring may be formed as a rectangular, square or hexagonal surround.

In the case of the concrete sleeper according to the invention, the ring is consequently clamped at the top and bottom, since it lies at the top against or on the step of the clearance in the concrete sleeper and lies at the bottom against or on the step of the anchor block. What is essential here is that the ring is mounted or supported at the top on its outer side and at the bottom on its inner side. This results in the previously explained parallelogram-like shearing deformation, which allows a certain vertical movement of the mounted concrete sleeper. This shearing deformation has the advantage that the ring is only subjected to moderate loading thereby, as a result of which a long service life can be expected.

The invention relates furthermore to a solid carriageway, comprising a number of concrete sleepers of the type described, which are embedded in a top layer or a supporting layer, the top layer or the supporting layer having on its upper side clearances for the anchor blocks that are filled with a casting compound.

Further advantages and details of the invention are explained below on the basis of an exemplary embodiment with reference to the drawings. The drawings are schematic representations in which:

FIG. 1 shows a side view of a concrete sleeper according to the invention;

FIG. 2 shows a plan view of the concrete sleeper from FIG. 1;

FIG. 3 shows a sectional view taken in the transverse direction of a sleeper embedded in a solid carriageway; and

FIG. 4 shows a longitudinal section of the concrete sleeper according to the invention embedded in a solid carriageway.

The concrete sleeper 1 shown in FIGS. 1 and 2 in a side view and a plan view is formed as a wide sleeper and comprises two sleeper blocks 2, 3, on the upper side of which rail beds 4, 5 are formed. The two sleeper blocks 2, 3 are connected to one another by a middle section 6, which—as can be seen in FIG. 2—has a smaller width than the sleeper blocks 2, 3. The wide sleeper that is described in this exemplary embodiment should not be understood as a restriction, since the concrete sleeper may also be of some other form, for example a cuboidal form. With the rail beds 4, 5 and the middle section 6, the sleeper blocks 2, 3 form an integral, monolithic component. Respectively arranged under the sleeper blocks 2, 3 is a base 7, 8 of an elastic material. In the exemplary embodiment represented, the base consists of EPDM (ethylene-propylene-diene monomer) and has a thickness of 14 mm. However, the thickness indicated should not be understood as a restriction; rather, the thickness of the base may typically be between 6 and 20 mm; the base thickness used is set within the limits of the stiffness and the tuning frequency of the concrete sleeper.

On its underside, the concrete sleeper 1 has in its middle section 6 an annular recess 9, into which an anchor block with an elastomer ring can be inserted. In the fitted state, the concrete sleeper 1 is coupled via the anchor block to the supporting layer of a solid carriageway, so that horizontal forces can be transferred into the underlying ground. Vertical forces are introduced from the concrete sleeper 1 into the supporting layer via the base 7, 8. In the case of a solid carriageway, at least every second or third concrete sleeper is provided with an anchor block.

FIG. 3 shows the concrete sleeper 1 in a section taken in the transverse direction in the region of its recess, after it has been fitted into a solid carriageway. The concrete sleeper 1 has a number of reinforcing rods 10, 11, which may be untensioned or pretensioned. Arranged under the concrete sleeper 1 is an anchor block 12, which is secured by a mounting band 13. Between the anchor block 12 and the concrete sleeper 1 there is an elastic ring 14, which is produced from an elastomer. In FIG. 3 it can be seen that the anchor block 12 has a step 15. The anchor block 12 has a greater diameter under the step 15 than above the step 15. The outer edge formed by the anchor block 15, on which a corner of the ring 14 lies, is rounded. In FIG. 3 it can also be seen that the ring 14 lies approximately with half its width on the rounded step 15; the outer corner of the ring 14 is in contact with a side face 16 of the recess 9. The outer corner of the ring 14 is not vertically mounted, so that the ring 14 can at least slightly move vertically. A clear space is formed between the upper side of the anchor block 12 and the underside of the recess 9.

The recess 9 in the concrete sleeper 1 has a peripheral step 17 with an outwardly increased diameter; the ring 14 lies with its upper outer corner against this step 17. Like the step 15, the step 17 is rounded, thereby avoiding damage to the ring 14 when it undergoes deformation under load. In FIG. 3 it is shown that the ring 14 lies approximately over half its radial width against the step 17 of the recess 9 in the concrete sleeper 1.

In the production of a solid carriageway, an asphalt supporting layer 18 is provided with clearances 19 for the anchor blocks 12. The clearances 19 are cylindrically formed and adapted to the size of the anchor blocks 12; the depth of the clearances 19 is chosen such that a clear space 20 remains under the anchor block inserted together with the concrete sleeper and is subsequently cast with a casting compound or a casting mortar 21 after the positioning and alignment of the concrete sleeper 1. Casting slits 22, through which the casting compound 21 is introduced, extend laterally from the clearance 19.

The concrete sleepers 1 have rail fastenings, which—unlike in the case of conventional solid carriageways—are not highly elastic rail fastenings. The rail fastenings used allow compensation in the vertical and lateral directions. The vertical compensation is made possible by shims of varying thickness, the lateral compensation by angled guiding plates of varying width. In addition, there is a hard intermediate layer, which is arranged between the rail and the surface of the concrete sleeper and consists of EVA (ethylene vinyl acetate).

FIG. 4 shows a solid carriageway 23 comprising the concrete sleeper 1, mounted on which are rails 24, which are held by rail fastenings 25. The concrete sleeper 1 is connected via the anchor block 12 to an asphalt top layer 26, which is located above an asphalt supporting layer 27. The asphalt supporting layer, produced in multiple layers, is mounted on a frost protection layer 28. The loads occurring when the solid carriageway 23 is passed over are substantially introduced via the bases 7, 8 arranged under the concrete sleeper 1 into the asphalt top layer 26. Settlements of typically 1.5-4 mm occur thereby. This produces the advantage that the entire mass of the concrete sleeper 1 is elastically mounted, whereby the tuning frequency of transferred vibrations is lowered. On the other hand, the spring stiffness of the base 7, 8, which has the function of a spring in the spring-mass system, is of a soft design, which similarly has a positive effect on the tuning frequency.

When it is passed over by rail vehicles, the sleeper is moved vertically down and subsequently up again. The ring 14 can absorb these movements with almost no wear, since it lies at two diagonally opposite corners against the anchor block 12 on the one hand and against the recess 9 in the concrete sleeper 1 on the other hand.

In the case of another configuration, the solid carriageway is produced in a concrete type of construction. In this case, the concrete sleepers are mounted on a concrete supporting layer by means of the anchor block. 

1-14. (canceled)
 15. A concrete sleeper for a solid carriageway, with an anchor block having a step with a downwardly increased diameter, which block is inserted with its upper section into an underside recess in the concrete sleeper and is mounted elastically by means of a ring produced from an elastomer and which can be inserted with its lower section into a fillable clearance in a top layer of the solid carriageway, wherein a base of an elastic material is arranged on the underside of the concrete sleeper, in that the outer edge of the step of the anchor block is rounded and in that the underside recess in the concrete sleeper has a peripheral step, against which the ring lies with its upper outer corner.
 16. The concrete sleeper as claimed in claim 15, wherein the base consists of EPDM (ethylene-propylene-diene monomer).
 17. The concrete sleeper as claimed in claim 15, wherein the base has a thickness of 6 to 20 mm, preferably 8 to 14 mm.
 18. The concrete sleeper as claimed in claim 15, wherein the base is provided with a nonwoven on one or both sides.
 19. The concrete sleeper as claimed in claim 15, wherein the base has a clearance in the region of the underside recess for the anchor block or is formed as two parts and is arranged only under sleeper blocks or partially under rail beds.
 20. The concrete sleeper as claimed in claim 15, wherein less than half the radial width of the ring lies on the step of the anchor block.
 21. The concrete sleeper as claimed in claim 15, wherein the step is rounded.
 22. The concrete sleeper as claimed in claim 15, wherein less than half the radial width of the ring lies against the step of the concrete sleeper.
 23. A solid carriageway, comprising a number of concrete sleepers as claimed in claim 15, which are embedded in a top layer or a supporting layer, the top layer or the supporting layer having clearances for the anchor blocks that are filled with a casting compound.
 24. The solid carriageway as claimed in claim 23, wherein the top layer and the supporting layer are produced from asphalt or in that the supporting layer is produced from concrete.
 25. The solid carriageway as claimed in claim 23, wherein the concrete sleepers have rail fastenings with means for vertical and lateral compensation and/or a hard intermediate layer of EVA (ethylene vinyl acetate). 